PCIC SCIENCE BRIEF : SPREAD IN MODEL CLIMATE SENSITIVITY TRACED TO ATMOSPHERIC CONVECTIVE MIXING
PCIC SCIENCE BRIEF : SPREAD IN MODEL CLIMATE SENSITIVITY TRACED TO ATMOSPHERIC CONVECTIVE MIXING
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1.这里的"可能"定义为评估的可能性为66 - 100%。2.这些数字来自第一工作组对IPCC第五次评估报告的贡献的技术摘要。这份摘要与完整的报告和一份高级别的概述文件《决策者摘要》一起可从IPCC的网站上获得：地球大气层的一部分，最接近海洋表面并直接受到海洋表面的影响，一般厚约1公里至2公里。5.这里，σ是标准偏差，是测量值平均值的扩展度量。对于2 σ范围，如果观测值具有钟形"正态"概率分布，则约95.4%的观测值将位于阴影内。预测人为气候变化将产生的影响的程度部分取决于气候系统变化的程度和速度。而这又在很大程度上取决于气候系统对大气温室气体浓度变化的敏感程度。地球气候系统的平衡气候敏感性，通常被称为“气候敏感性”，被定义为如果大气中二氧化碳浓度增加一倍并保持不变，最终将在地球平均表面温度中看到的变暖量。政府间气候变化专门委员会（IPCC）指出，根据观测、气候反馈机制研究、古气候数据（如冰芯和树木年轮）和全球气候模型（GCM），气候敏感性的可能1范围2在1.5 ° C至4.5 ° C之间。现代大气环流模式的平均值为3.2 ° C，最接近现代气候的模式的数值在3 ° C至4 ° C之间。舍伍德、Bony和Dufresne（2014年）利用卫星观测、再分析数据和参加耦合模式相互比较项目3（CMIP 3和CMIP 5）第三和第五阶段的模式的GCM输出，研究了GCM之间GCM气候敏感性的变化在多大程度上可以用模式代表大气垂直混合的不同能力来解释。他们分析的垂直混合是由两个浅（~5公里），垂直，翻转的空气循环模式组成的，它干燥了海洋边界层4，减少了使地球降温的低云的形成。
1. Here 'likely' is defined as having an assessed likelihood of 66-100%. 2. These figures are from the Technical Summary of Working Group One's contribution to the Fifth Assessment Report of the IPCC. This Summary is available—along with the full report and a high-level overview document, the Summary for Policymakers—from the IPCC's website: part of the Earth's atmosphere that is closest to and directly affected by the ocean's surface, generally about 1 km to 2 km thick. 5. Here, σ is a standard deviation, a measure of the spread from the average of the measurements. For the 2σ range, about 95.4% of observations will lie within the shading if observations have a bell-shaped " normal " probability distribution. The magnitude of the impacts that are projected to occur as a result of anthropogenic climate change depend, in part, on the magnitude and rate of the changes to the climate system. These, in turn, depend largely on how sensitive the climate system is to changes in the concentration of atmospheric greenhouse gases. The equilibrium climate sensitivity of the Earth's climate system, often just referred to as " climate sensitivity, " is defined as the amount of warming that would eventually be seen in the Earth's average surface temperature if the atmospheric concentration of carbon dioxide were to be doubled and then held constant. The Intergovernmental Panel on Climate Change (IPCC) states that the likely 1 range 2 of climate sensitivity , from observations, studies of climate feedback mechanisms, paleoclimate data (such as ice cores and tree rings) and Global Climate Models (GCMs) is between 1.5 °C to 4.5 °C. The mean value for modern GCMs is 3.2 °C and the models that most closely simulate the modern climate have values in the range of 3 °C to 4 °C. Using satellite observations, reanalysis data and GCM output from models that participated in the third and fifth phases of the Coupled Model Intercomparison Project 3 (CMIP3 and CMIP5), Sherwood, Bony and Dufresne (2014) examine how much of the variation in GCM climate sensitivity between GCMs can be explained by the differing ability of the models to represent vertical mixing of the atmosphere. The vertical mixing that they analyze in is made up of two shallow (~ 5 km), vertical, overturning air circulation patterns that dry the marine boundary layer 4 , which reduces the formation of low clouds that cool the Earth …